public interface TTTInterface
{
    // eval:  Return 1 if White has three in a row, three in a column, or
    //   three on either diagonal.  Return -1 if Black has three in a row,
    //   three in a column, or three on either diagonal.  Both of these
    //   conditions can't apply in a real game; if they do, either 1 or -1
    //   is an acceptable value to return.  If none of these conditions
    //   apply, it should return 0.
    public int eval ();
    //
    // isDraw:  Determine whether the game is a draw.
    // Return true if there are no unfilled spaces and neither player
    //  has three in a row.  Otherwise, return false.
    public boolean isDraw ();

    // stateScore:  whiteMove is true if it's white's move, and false
    //  if it's black's move.  BestMove is an array of at least two integers.
    //  There is no precondition on what values it must contain.
    //  Postcondition:  It should return 1 if white has won or can force
    //  a win, -1 if black has won or can force a win, and 0 if neither
    //  can force a win, which means that the game is destined to be a draw
    //  (unless somebody makes a mistake).  Bestmove has been filled
    //  which the row and column of a move that leads to a new board state
    //  that has this same state score.  Such a move is a best move
    //  a player can make.  See handout for hints about how to proceed.
    public int stateScore (boolean whiteMove, int [] BestMove);
}